HOOVER, Ala. -- Just when the LSU baseball team looked to be on the losing end for the first time in 31 days, the Tigers rallied for four runs in the bottom of the ninth before Blake Dean hit a walk-off solo home run with one out in the 10th to advance in the Southeastern Conference Tournament, 5-4, on Wednesday afternoon.

After an amazing four-run rally in the bottom of the ninth, LSU advanced to the winners' bracket of the double-elimination tournament and will face the winner of today's Florida-Vanderbilt game (1 p.m.) on Thursday at 5 p.m. CDT.

The Tigers (40-16-1) have won 17-straight games, the longest streak in the nation.

Tigers starter Ryan Verdugo didn't figure into the decision after giving up three runs on only four hits in six innings while striking out 10. Five walks came back to haunt him, especially in the top of the sixth inning when he walked the bases loaded before USC's Harley Lail hit a two-RBI bloop single to left field.

LSU reliever Louis Coleman gave up a leadoff walk to USC's DeAngelo Mack in the top of the ninth who came around to score on a single by Reese Havens, giving USC a 4-0 lead.

In his first SEC start of his career, South Carolina starter Sam Dyson was stellar, allowing only two hits and three walks in 6 2/3 innings. He left the game with a 3-0 lead.

In the seventh inning, Will Atwood entered in relief but couldn't complete the combined shutout. He walked LSU designated hitter Blake Dean and catcher Micah Gibbs to open the bottom of the ninth inning. Tigers slugger Matt Clark then tagged a first-pitch three-run home run to right-center field to cut the deficit to 4-3.

With one out in the ninth, righthander Brandon Todd replaced Atwood. He walked Tigers shortstop DJ LeMahieu before left fielder Nicholas Pontiff was called out on strikes on a low curve ball -- a call that brought Coach Paul Mainieri out of the dugout on fire.

With two outs and the tying run at first, second baseman Ryan Schimpf blooped what looked to be a foul ball toward left field. However, USC left fielder Andrew Crisp gave up on the ball which landed in fair territory and allowed LeMahieu to score from first and tie the game at 4-4.

LSU all-purpose pitcher Jared Bradford (10-4) earned the win after pitching through a leadoff walk in the top of the 10th.

Gamecocks lefty Alex Farotto struck out Jared Mitchell to start the 10th inning, but Dean hit a 2-0 pitch over the right-center field fence for his 14th homer of the season, ending the game.